This invention relates generally to computer systems, and to graphical user interfaces for computer systems. More specifically, the invention pertains to systems for organizing handwritten images in a document.
Computerized personal organizers are becoming increasingly popular. They perform such functions as keeping a calendar, an address book, a to-do list, etc. While these functions can be provided by conventional computer systems, they are more conveniently provided by personal organizers which are relatively inexpensive, small, and lightweight (i.e. portable). Personal organizers are available from such companies as Sharp and Casio of Japan.
A relatively new form of computer, the pen-based computer system, holds forth the promise of a marriage of the power of a general purpose computer with the functionality and small size of a personal organizer. A pen-based computer system is typically a small, hand-held computer where the primary method for inputting data includes a "pen" or stylus. A pen-based computer system is commonly housed in a generally rectangular enclosure, and has a dual-function display assembly providing a viewing screen along one of the planar sides of the enclosure. The dual-function display assembly serves as both an input device and an output device. When operating as an input device, the display assembly senses the position of the tip of a stylus on the viewing screen and provides this positional information to the computer's central processing unit (CPU). Some display assemblies can also sense the pressure of the stylus on the screen to provide further information to the CPU. When operating as an output device, the display assembly presents computer-generated images on the screen.
The dual-function displays of pen-based computer systems permit users to operate the computers as computerized notepads. For example, graphical images can be input into the pen-based computer by merely moving the stylus across the surface of the screen. As the CPU senses the position and movement of the stylus, it generates a corresponding image on the screen to create the illusion that the stylus is drawing the image directly upon the screen, i.e. that the stylus is "inking" an image on the screen. With suitable recognition software, the "ink" can be identified as text and numeric information.
One of the most desirable functions of a pen-based computer system is the ability to take and retrieve notes. In the past, however, the entry of text and graphics into a pen-based computer system has been severely limited by constraints imposed by the pen-based computer's operating system. For example, text typically had to be entered in small boxes or fields, and usually the location for insertion of text was specifically identified. Further, the ability to reformat material entered into prior pen-based computer systems was quite limited. Often a user will wish to have rough handwritten notes organized in easy-to-read straight lines and paragraphs. Thus, there remains a need for a system that can accept ink notes jotted anywhere on a screen and then organize them in a consistent and convenient format.